Metal casting is the process of creating objects by filling a cavity with molten metal and letting the metal cool. One common metal casting process is sand casting. In sand casting, a pattern is fabricated as a replica of a finished object. The pattern is placed in a two-piece mold containing sand and additional sand is packed tightly around the pattern. The pattern is removed from the mold creating a cavity in the sand. Molten non-ferrous metal such as aluminum, brass, copper or bronze is introduced into the cavity. After cooling, the cast object is removed from the mold. The metal casting process can be used for creating panels such as wall plaques, and lawn or memorial markers. Memorial markers are typically formed from bronze and include raised lettering which indicates the name, dates of birth and death of the deceased and may also include an epitaph in the form of a memorial prayer or verse.
Traditionally, a pattern is prepared by manually fixing raised lettering or other decorative features to a blank or pre-decorated pattern. Decorative features may include bas relief decorations. For example, a sculpture may sculpt a low profile, three-dimensional representation of the deceased's head out of clay which is then fixed to the pattern. Another known pattern preparation technique involves the use of placing a negative of the desired lettering on a photosensitive material and then exposing the material to a UV light source.
Another known pattern preparation process involves the use of a computer-aided design/computer-aided manufacturing (CAD/CAM) software program operable on a processor which controls the tool path of a routing table. In this process, line art is either scanned into or created in the computer and the elevation of the cut lines is determined by the computer operator. Once the elevation and contours are determined by the computer operator, a tool path is created for use by the CAD/CAM machine. The CAD/CAM machine is then used to route a pattern for use in the foundry. This known process is limited to the use of line art which is difficult to use to recreate detailed photograph-like images.
It has been found to be difficult to create minutely detailed, three-dimensional, photograph-like images using the above-described pattern preparation processes.